On the East Frisian island of Borkum, a bride disappears shortly before her wedding. At first, detectives Mona Sander and Enno Moll think it's a stupid prank. But a little later, the bloodstained wedding dress is found. Has the dark-haired beauty fallen victim to a violent crime? The island detectives find clues, but they don't add up. Is the bride's obscure ex-boyfriend involved? Who was involved in the secret sex games in the holiday home? And what interest is the power-obsessed future father-in-law pursuing? Then the police find a body - and realise that things are very different from what they seem at first glance. The hunt for the murderer not only throws the peaceful North Sea island into turmoil, but also becomes a personal challenge for Mona Sander. She herself becomes the target of the murderer.